This is the 4th step to remove the debug info of DISK_ALLOC.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

This is the 3rd step to remove the debug info of DISK_ALLOC.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

This is the 2nd step to remove the debug info of DISK_ALLOC.

So this patch removes all mlog(0,...) from localalloc.c and adds
the corresponding tracepoints. Different mlogs have different
solutions.
1. Some are replaced with trace event directly.
2. Some are replaced while some new parameters are added.
3. Some are combined into one trace events.
4. Some redundant mlogs are removed.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

This is the first try of replacing debug mlog(0,...) to
trace events. Wengang has did some work in his original
patch
http://oss.oracle.com/pipermail/ocfs2-devel/2009-November/005513.html
But he didn't finished it.

So this patch removes all mlog(0,...) from alloc.c and adds
the corresponding trace events. Different mlogs have different
solutions.
1. Some are replaced with trace event directly.
2. Some are replaced and some new parameters are added since
   I think we need to know the btree owner in that case.
3. Some are combined into one trace events.
4. Some redundant mlogs are removed.
What's more, it defines some event classes so that we can use
them later.

Cc: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

About one year ago, Wengang Wang tried some first steps
to add tracepoints to ocfs2. Hiss original patch is here:
http://oss.oracle.com/pipermail/ocfs2-devel/2009-November/005512.html

But as Steven Rostedt indicated in his article
http://lwn.net/Articles/383362/, we'd better have our trace
files resides in fs/ocfs2, so I rewrited the patch using the
method Steven mentioned in that article.
Signed-off-by: NWengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: NTao Ma <boyu.mt@taobao.com>